This invention relates to circuit breaker accessories, and, more particularly to gap control mechanisms for circuit breaker accessories.
Circuit breakers commonly implement accessories to add various functionalities. These accessories may provide a mechanical force to an operating mechanism of a circuit breaker, for example, in response to a trip event that provides an electronic signal to interrupt the circuit (i.e., electronic trip actuators, shunt trip actuators, under voltage actuators, etc.).
Accessories typically include movable linkages and members that change position to perform a function upon occurrence of a trip event. For example, the accessory may include an actuating mechanism that acts on a link in response to a trip event, such as the overcurrent conditions detected from various circuitry. The link, when not acted upon, engages or holds a trip member against the bias of a spring. When the link is acted upon, it disengages or releases the trip member, whereby the bias of the spring acts on the trip member. The trip member then provides a mechanical force to a circuit interrupter. However, after use, the trip member must be reset to the original, ready to trip position. After resetting, it is desirable that the space between the actuating mechanism and the link is consistently maintained so the release of the trip member is properly effectuated.
Furthermore, it is desirable to provide an engagement that prevents the members from becoming disengaged from each other due to vibrations occurring under normal operating conditions (commonly referred to as "shock-out"). It is also important that the engagement be quickly and reliable releasable upon occurrence of a trip event so that the motion of the members, hence the force provided to the operating mechanism, is rapid and unhindered.
For the foregoing reasons, there exists a particular need for an arrangement between movable members that consistently provides the desired spacing between the members, securely maintains the engagement between the members, and allows for rapid disengagement of the members upon occurrence of an event, i.e., a trip event.